John Dies At The End is the gonzo novel-turned-movie, written by surrogate author David Wong (actually Jason Pagrin). It’s his story about Soy Sauce, the latest and craziest drug on the street. After ingesting it, you can cross time and dimensions and, as John discovers, also die. Or does he? Watch the trailer to find out more.

The film is directed by Phantasm and Bubba Ho-Tep helmer Don Coscarelli, and it’s every bit as off-kilter as his previous cult offerings. We chatted to the author to find out what he really thinks of the adaptation and how exactly he came up with a premise so strange…

How did you develop the initial idea for the story?

The first step was spending about 26 years developing various psychological and emotional imbalances. I largely avoided making friends, and started reading horror novels at around age 9. By the early 2000s I was working in an insurance office and, as a way to blow off steam, would write dark, absurdist articles on the internet under a fake name. Finally, one Halloween I started writing John Dies At The End, which was an experiment to see how much gruesome horror and surreal plot twists a reader could tolerate before pitching their computer out of the window.

As for how I came up with the story itself, it started with the narrator – I wanted to tell a bizarre, nightmarish tale through the eyes of this deadpan, apathetic protagonist who mostly just wants to go back home. So it was just a matter of sending Dave down through the rabbit hole (via this mysterious drug) and having fun imagining how he would react to each new hell he faced.

The film is a race car. It’s a faster, louder, more stripped-down version. The book already zips frantically from one surreal plot twist to the next, but the pressures of time constraints force the film to move even faster, and to give the audience even less time to wrap their heads around what’s happening. All of the actors are larger-than-life personalities and everyone chews scenery in a way that goes ridiculously beyond what’s on the page. I love it.

Were the actors similar to how you imagined the characters?

No one looks exactly like their counterpart in my brain, but of course at the casting stage getting the right performance is a thousand times more important than getting with the right look (for instance, Dave is overweight in the book, Chase Williamson is not. But Chase gives the most perfect performance imaginable).

What do you feel the director Don Corscarelli brought to the picture?

He was one of the few filmmakers on Earth, maybe the only one, who could look at this story and say, “How can we make this more ridiculous?” There are all of these beautiful little touches, from the accent Clancy Brown brought to his role to the skull on John’s fireproof facemask, all these dozens of little bits of flair that remind you why he’s one of the greats. No one else would have gotten the same result.

Do you know if the sequel will be adapted too?

No word on that yet. I have a feeling it will have something to do with how many people pay to see this one!

John Dies At The End and the sequel, This Book Is Full Of Spiders: Seriously Dude Don’t Touch It are out now from Titan Books, pick up the first book for £6.39 and the second for £6.99 from Amazon.co.uk. The movie is in cinemas from 22 March 2013.